Dave …
I’ve been following this mystery since your first post. Lots of very
experienced people contributing (including yourself), so I’m sure the solution
will surface shortly.
One thing that I just now recalled. I no longer have your initial post handy,
but remember that the initial test with the dipole hung up in free space away
from the tower was very good. In fact, so good that it seemed suspicious. I
think the SWR was something like 1.1 over the entire 40 meter band?
Don’t know what height the dipole was, but even a perfect dipole won’t be that
close to 50 ohms at most heights. And, would expect to see some variation
over the band.
Questions:
How long is the coax and what type?
You said you had a balun at the feed point. I assume it is a choke with the
coax wound around ferrite?
How were you measuring the SWR?
One possibility is that you perhaps had some unintentional losses (or
measurement error) in your first test that went away when you mounted the
dipole to the tower?
73 Craig AC0DS
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